Goryeo, also spelled as Koryŏ (Hangul: 고려; Hanja: 高麗; Korean pronunciation: [koɾjʌ]; 918–1392), was a Korean dynasty established in 918 by King Taejo. This kingdom later gave name to the modern exonym "Korea".[2] It united the Later Three Kingdoms in 936 and ruled most of the Korean Peninsula until it was removed by the founder of the Joseon in 1392. Goryeo expanded Korea's borders to present-day Wonsan in the northeast (936–943), the Yalu River (993) and finally almost the whole of the Korean Peninsula (1374).

Two of this period's most notable products are celadon pottery and the Tripitaka Koreana—the Buddhist canon (Tripiṭaka) carved onto more than 80,000 woodblocks and stored (and still remaining) at Haeinsa. The people of Goryeo also created the first metal movable type that was capable of printing actual books, in 1234;[3][4][5] the oldest surviving metal movable type book, the Jikji, was printed in 1377.[6]

In 668, Silla conquered Baekje and Goguryeo with an alliance with Tang China, but by the late 9th century it was tottering, its monarchs being unimaginative and pressed by the power of powerful statesmen. Many robbers and outlaws agitated and in 900 Gyeon Hwon revolted from Silla control in the Jeolla region as the state of Later Baekje; the year after, Gung Ye revolted from the northern regions as Taebong. A son of a regional lord, Wang Geon, joined Taebong as a general.

Taebong fell when Wang Geon revolted and killed Gung Ye in 918; he was crowned Taejo of Goryeo in June of the same year. Silla was overpowered by Goryeo and Later Baekje and surrendered to Goryeo in 935. In 936, Later Baekje surrendered and Goryeo subsequently maintained an unbroken dynasty that ruled Korea for 474 years, although the government was controlled by military regime leaders between 1170 and 1270.

The name Goryeo is derived from Goguryeo of the Three Kingdoms of Korea, which the Goryeo state regarded as its predecessor.[7][8][9][10] Goguryeo changed its name to Goryeo during the reign of Jangsu in the 5th century. The English name "Korea" derives from Goryeo (also spelled as Koryŏ).[11]

Wang Geon, who later became the Taejo of Goryeo, joined Later Goguryeo as a general but later overthrew Gung Ye and established the state of Goryeo in 918.[12] Goryeo regarded itself as the successor of Goguryeo.[7][8][9][10] Wang Geon, the founder of Goryeo, was a descendant of Goguryeo,[13] and traced his ancestry to a noble Goguryeo clan.[14]

Goryeo adopted a Later Silla-friendly, Later Baekjae-hostile stage during the Later Three Kingdoms, but in 927, Goryeo was defeated by Later Baekje in present-day Daegu and King Taejo lost his most able supporters in the battle. For three years after, Later Baekje dominated the Later Three Kingdoms, but after a defeat at Andong in 930, it lost its power.

The Later Three Kingdoms era ended when Goryeo annexed Silla in 935 and defeated Later Baekje in 936. King Taejo moved the capital to his hometown of Kaesǒng, and ruled the Korean peninsula as the first King of Goryeo. Taejo married a daughter of the Silla royal family and allowed most of their nobility to keep their lands. Even though he ruled the united nation for only seven years before his son took the throne upon his death, the succession was not challenged.[15]

In 937, one year after the unification of the Later Three Kingdoms, much of the ruling class and the last crown prince of Balhae fled to Goryeo, where he was warmly welcomed and included into the ruling family by Wang Geon, thus unifying the two successor nations of Goguryeo.[16]

The terminology used in the court of Goryeo was that of an empire, not of a kingdom. The capital, Gaegyeong (Hangul: 개경(開京)) was called Hwangdo "Imperial Capital" (Hangul: 황도(皇都)) and the palace was referred to as "Imperial Palace" (Hangul: 황성(皇城)). The nation also utilized a system of multiple capitals: Gaegyeong as the main capital, and Seogyeong (Hangul: 서경(西京), modern Pyongyang), Namgyeong (Hangul: 남경(南京), modern Seoul) and Donggyeong (Hangul: 동경(東京), modern Gyeongju) as secondary capitals. The mere use of this system and the nomenclature or use of the character 京(경) implied that Goryeo functioned internally as an empire.

However, Goryeo, when enshrining its rulers, did not use the title "Emperor" (Hangul: 황제(皇帝)). Instead, the title of "Great King" (Hangul: 대왕(大王)) was used to posthumously enshrine Goryeo monarchs. When enshrining its rulers, however, it did use temple names such as Taejo (Hangul: 태조(太祖)); this is a practice kingdoms did not take part in. Imperial titles, like Emperor or "Emperor of the east of the sea (Hangul: 해동천자(海東天子))" were also used.

The Song and Liao dynasties of China tolerated Goryeo's imperial claims and practices.[17] In contrast, after the Mongol invasions, all of these terms were prohibited by Mongol rulers and Goryeo monarchs were forced to insert the character 忠 "loyal" (Hangul: 충) into their posthumous enshrinement names. This is why the monarchs after Wonjong had this character in their posthumous names until Gongmin. As Mongol power diminished, rulers no longer used 忠 but still were unable to restore the use of the temple name.

In order to strengthen the power of the central government, Gwangjong, the fourth emperor, made a series of laws, including that of freeing slaves in 958 and one creating the exam for hiring civil officials. To assert power internationally, Gwangjong also proclaimed Goryeo an empire independent from any other country of its day.

The fifth king, Gyeongjong, launched land-ownership reformation called the "Jeonsigwa" (Hangul: 전시과(田柴科)) and the 6th king, Seongjong appointed officials to local areas, which were previously succeeded by the lords. Between 993 and 1019, the Goryeo–Khitan War ravaged the northern border.

By the time of eleventh king, Munjong, the central government of Goryeo has gained complete authority and power over local lords. Munjong and later kings emphasized the importance of civilian control of the military.

The Jurchens in the Yalu River region were tributaries of Goryeo since the reign of Wang Geon, who called upon them during the wars of the Later Three Kingdoms period, but the Jurchens switched allegiance between Liao and Goryeo multiple times, taking advantage of the tension between the two nations; posing a potential threat to Goryeo's border security, the Jurchens offered tribute to the Goryeo court, expecting lavish gifts in return.[18] According to the Goryeosa, in 918, the ancient capital of Pyongyang had been in ruins for a long time and foreign barbarians were using the surrounding lands as hunting grounds and occasionally raiding the borders of Goryeo; therefore, Wang Geon ordered his subjects to repopulate the ancient capital,[19] and soon sent his cousin Wang Sik-ryeom to defend it.

In 993, the Khitan Liao dynasty invaded Goryeo's northwest border with an army that the Liao commander claimed to number 800,000.[20][21] After a military stalemate,[22] the Goryeo diplomat, Seo Hui, negotiated with the chief Liao general and reached a settlement. In the settlement, Goryeo agreed to end its alliance with Song China, to adopt Liao's calendar, and to become a Liao tributary state.[20][23][24][25][26][27][28] Seo Hui negotiated and obtained Liao consent to incorporate the land between the border of Liao and Goryeo up to the Yalu River, which was at the time occupied by troublesome Jurchen tribes, citing that in the past the land belonged to Goguryeo, the predecessor to Goryeo.[20][29][30][31] With this settlement the Liao withdrew, but Goryeo continued to communicate with the Song,[32] having strengthened its defenses by building a fortress in the newly gained northern territories.[20]

In 1009, General Gang Jo of Goryeo led a coup against King Mokjong, killing him and establishing military rule.[33] The Liao attacked with 400,000 troops in 1010, claiming to avenge the murdered Mokjong.[34][35]

Gang Jo blocked the Liao's first attack, but he was defeated in the second one and was executed.[21][36]King Hyeonjong of Goryeo was forced to flee the capital, which was sacked and burnt by the Khitan,[35][37][38] to Naju temporarily.[21] Unable to establish a foothold and fearing a counterattack by the regrouped Korean armies, the Khitan forces withdrew.[37] Afterward, the Goryeo king sued for peace, but the Liao emperor demanded that he come in person and also cede key border areas; the Goryeo court refused the demands, resulting in a decade of hostility between the two nations, during which both sides fortified their borders in preparation of war.[39] Liao attacked Goryeo in 1015, 1016, and 1017, but the results were indecisive.[40]

General Yun Gwan (1040-1111) and his army.

In 1018, Liao assembled an army of 100,000 troops to invade Goryeo. In preparation, General Gang Gam-chan ordered a stream to the east of Heunghwajin to be dammed. When the Khitan troops crossed the Yalu River, Gang Gam-chan opened the dam and attacked the enemy troops with 12,000 mounted troops, catching them by surprise, inflicting severe losses, and cutting off their line of retreat.[41] The Khitan troops soldiered on and headed toward the capital, but were met with stiff resistance and constant attacks, and were forced to retreat back north.[41] Gang Gam-chan and his troops waited at Gwiju and surrounded the Khitan, annihilating most of them.[41] Barely a few thousand Liao troops survived after the Battle of Gwiju.[42]

In the late summer of 1019, the Liao assembled another large army.[42] Both sides recognizing the difficulty of achieving a decisive victory, King Hyeonjong sent a tributary mission to the Liao in 1020 and Emperor Shengzong graciously pardoned him.[42] After that, the tributary relationship between Goryeo and Liao was resumed[42] and Goryeo suspended its relationship with the Song.[43] Goryeo had no more conflicts with the Liao state,[44] and Goryeo no longer feared Liao.[45] Beginning in the 1030s, Goryeo resumed unofficial contacts with Song and received hundreds of merchant ships each year.[46] However, Goryeo was viewed with apprehension by some in the Song court;[47] in addition, Goryeo was considered the only state not to be conquered by Liao,[48] and was thought to be feared by Liao.[49]

After Goryeo's victories over Liao, Goryeo experienced a golden age that lasted a century, during which there were great developments in printing and publishing, promoting learning and dispersing knowledge on philosophy, literature, religion, and science; by 1100, there were 12 universities that produced famous scholars and scientists.[50][51] In 1087, the first version of the Tripitaka Koreana was completed after many years of labor.

The Jurchens north of Goryeo had traditionally rendered tribute to the Goryeo monarchs and called Goryeo their "parent country",[52][53][54] but thanks to the defeat of Liao in 1018, the Wanyan tribe of the Heishui Mohe unified the Jurchen tribes and gained in might.

In 1107, General Yun Gwan led a newly formed army, a force of approximately 17,000 men called the Byeolmuban, and attacked the Jurchen. Though the war lasted for several years, the Jurchen were ultimately defeated, and surrendered to Yun Gwan. To mark the victory, General Yun built nine fortresses to the northeast of the border (Hangul: 東北九城). In 1108, however, General Yun was given orders to withdraw his troops by the new ruler, King Yejong. Due to manipulation and court intrigue from opposing factions, he was discharged from his post. Opposition factions fought to ensure the new fortresses were turned over to the Jurchen.

During the reign of Jurchen leader Wuyashu in 1103-1113, the border between the two nations was stabilized and Korean forces withdrew from Jurchen territories, acknowledging Jurchen control over the contested region.[55][56]

To defend against the Jurchens and Khitans, a Long Wall was built by Goryeo in 1033-1034.[57][58][59][60][61]

The House Yi of Inju (Hangul: 인주이씨(仁州李氏)) married women to the kings from the time of Munjong to the 17th King, Injong. Eventually the House of Yi gained more power than the monarch himself. This led to the coup of Yi Ja-gyeom in 1126. It failed, but the power of the monarch was weakened; Goryeo underwent a civil war among the nobility.[62]

In 1135, Myocheong argued in favor of moving the capital to Seogyeong (present-day Pyongyang).[62] This proposal divided the nobles. One faction, led by Myocheong, believed in moving the capital to Pyongyang and expanding into Manchuria. The other one, led by Kim Bu-sik (author of the Samguk Sagi), wanted to keep the status quo. Myocheong failed to persuade the king; he rebelled and established the state of Daebang, but it failed and he was killed.[62]

Although Goryeo was founded by the military, its authority was in decline. In 1014, a coup occurred but the effects of the rebellion didn't last long, only making generals discontent with the current supremacy of the civilian officers.[63]

In addition, under the reign of King Uijong, the military officers were prohibited from entering the Security council, and even at times of state emergency, they were not allowed to assume commands.[64] After political chaos, Uijong started to enjoy travelling to local temples and studying sutra, while he was almost always accompanied by a large group of civilian officers. The military officers were largely ignored and were even mobilized to construct temples and ponds.[65]

In 1170, a group of army officers led by Jeong Jung-bu, Yi Ui-bang and Yi Go launched a coup d'état and succeeded.[66]King Uijong went into exile and King Myeongjong was placed on the throne. Effective power, however, lay with a succession of generals who used an elite guard unit known as the Tobang to control the throne: military rule of Goryeo had begun. In 1179, the young general Gyeong Dae-seung rose to power[67] and began an attempt to restore the full power of the monarch and purge the corruption of the state.

However, he died in 1183 and was succeeded by Yi Ui-min, who came from a nobi (slave) background.[67][68] His unrestrained corruption and cruelty[68] led to a coup by general Choe Chung-heon,[69] who assassinated Yi Ui-min and took supreme power in 1197.[66] For the next 61 years, the Choe house ruled as military dictators, maintaining the Kings as puppet monarchs;[70] Choe Chung-heon was succeeded in turn by his son Choe U, his grandson Choe Hang[71] and his great-grandson Choe Ui.[72]

When he took control, Choe Chungheon forced Myeongjong off the throne and replaced him with King Sinjong.[73] What was different from former military leaders was the active involvement of scholars in Choe's control, notably Prime Minister Yi Gyu-bo who was a confucian scholar-official.[70]

After Sinjong died, Choe forced his son to the throne as Huijong. After 7 years, Huijong led a revolt but failed. Then, Choe found the pliable King Gojong instead.[73]

Although the House of Choe established strong private individuals loyal to it, continuous invasion by the Khitan and Mongols ravaged the whole land, resulting in a weakened defense ability, and also the power of the military regime waned.[69]

Fleeing from the Mongols, in 1216 the Khitans invaded Goryeo and defeated the Korean armies multiple times, even reaching the gates of the capital and raiding deep into the south, but were defeated by Korean General Kim Chwi-ryeo who pushed them back north to Pyongan,[74][75] where the remaining Khitans were finished off by allied Mongol-Goryeo forces in 1219.[76][77]

In 1231, Mongols under Ögedei Khan invaded Goryeo following the aftermath of joint Goryeo-Mongol forces against the Khitans in 1219.[78] The royal court moved to Ganghwado in the Bay of Gyeonggi in 1232. The military ruler of the time, Choe U, insisted on fighting back. Goryeo resisted for about 30 years but finally sued for peace in 1259.

Meanwhile, the Mongols began a campaign from 1231 to 1259 that ravaged parts of Gyeongsang and Jeolla. There were six major campaigns: 1231, 1232, 1235, 1238, 1247, 1253; between 1253 and 1258, the Mongols under Möngke Khan's general Jalairtai Qorchi launched four devastating invasions against Korea at tremendous cost to civilian lives throughout the Korean peninsula.

Civilian resistance was strong, and the Imperial Court at Ganghwa attempted to strengthen its fortress. Korea won several victories but the Korean military could not withstand the waves of invasions. The repeated Mongol invasions caused havoc, loss of human lives and famine in Korea. In 1236, Gojong ordered the recreation of the Tripitaka Koreana, which was destroyed during the 1232 invasion. This collection of Buddhist scriptures took 15 years to carve on some 81,000 wooden blocks, and is preserved to this day.

In March 1258, the dictator Choe Ui was assassinated by Kim Jun. Thus, dictatorship by his military group was ended, and the scholars who had insisted on peace with Mongolia gained power. Goryeo was never conquered by the Mongols, but exhausted after decades of fighting, Goryeo sent Crown Prince Wonjong to the Yuan capital to swear allegiance to the Mongols; Kublai Khan accepted, and married one of his daughters to the Korean crown prince.[79] Khubilai, who became khan of the Mongols and emperor of China in 1260, did not impose direct rule over most of Goryeo. Goryeo Korea, in contrast to Song China, was treated more like an Inner Asian power. The dynasty was allowed to survive, and intermarriage with Mongols was encouraged, even with the Mongol imperial family, while the marriage between Chinese and Mongols was strictly forbidden when the Song dynasty was ended. Some military officials who refused to surrender formed the Sambyeolcho Rebellion and resisted in the islands off the southern shore of the Korean Peninsula.[80]

After 1270 Goryeo became a semi-autonomous client state of the Yuan dynasty. The Mongols and the Kingdom of Goryeo tied with marriages and Goryeo became quda (marriage alliance) vassal of the Yuan dynasty for about 80 years and monarchs of Goryeo were mainly imperial sons in-law (khuregen). The two nations became intertwined for 80 years as all subsequent Korean kings married Mongol princesses,[79] and the last empress of the Yuan dynasty was a Korean princess.[81] The kings of Goryeo held an important status like other important families of Mardin, the Uyghurs and Mongols (Oirats, Khongirad, and Ikeres).[82][83] It is claimed that one of Goryeo monarchs was the most beloved grandson of Kublai Khan.[84]

The Goryeo dynasty survived under the Yuan until King Gongmin began to push the Mongolian garrisons of the Yuan back in the 1350s. By 1356 Goryeo regained its lost northern territories.

Yeom Jesin (1304–1382) was the main political opponent of the monk, Shin Don, who was in power.

When King Gongmin ascended to the throne, Goryeo was under the influence of the Mongol Yuan China. He was forced to spend many years at the Yuan court, being sent there in 1341 as a virtual prisoner before becoming king. He married the Mongol princess Queen Noguk. But in the mid-14th century the Yuan was beginning to crumble, soon to be replaced by the Ming dynasty in 1368. King Gongmin began efforts to reform the Goryeo government and remove Mongolian influences.

His first act was to remove all pro-Mongol aristocrats and military officers from their positions. Mongols had annexed the northern provinces of Goryeo after the invasions and incorporated them into their empire as the Ssangseong (Hangul: 쌍성총관부(雙城摠管府)) and Dongnyeong Prefectures (Hangul: 동녕부(東寧府)). The Goryeo army retook these provinces partly thanks to defection from Yi Jachun, a minor Korean official in service of Mongols in Ssangseong, and his son Yi Seonggye. In addition, Generals Yi Seonggye and Ji Yongsu led a campaign into Liaoyang.

After the death of Gongmin's wife Noguk in 1365, he fell into depression. In the end, he became indifferent to politics and entrusted that great task to the Buddhist monk Shin Don (Hangul: 辛旽). But after six years, Shin Don lost his position. In 1374, Gongmin was killed by Choe Mansaeng (최만생) and others.

During this tumultuous period, Goryeo momentarily conquered Liaoyang in 1356, repulsed two large invasions by the Red Turbans in 1359 and 1360, and defeated the final attempt by the Yuan to dominate Goryeo when General Choe Yeong defeated an invading Mongol tumen in 1364. During the 1380s, Goryeo turned its attention to the Wokou menace and used naval artillery created by Choe Museon to annihilate hundreds of pirate ships.

During the 10th century, the Khitans tried to establish relations with Goryeo at least on two occasions. In 942, the Khitan ruler Taizu sent an embassy with a gift of 50 camels to Goryeo, but Taejo refused them, banishing the envoys and starving the camels to death.

Goryeo had maintained relations with most of the Five Dynasties[85] and southern kingdoms in China. By 962, formal relations were established with the Song dynasty. Relations with Song were close, with many embassies being exchanged between Goryeo and Song, but relations would be interrupted by the rise of the Liao and Jin dynasties.

After about 30 years of peace, the Khitans invaded Goryeo. After several military campaigns, a state of peace was established in 1020.[24] For around 100 years, the Far East was relatively peaceful and Munjong strengthened the Liao-Song-Goryeo line.

In 1102, the Jurchen threatened and another crisis emerged. In 1115 the Jurchen founded the Jin dynasty, and in 1125 Jin annihilated Liao, which was Goryeo's suzerain,[24] and started invasion of Song. In response to the circumstantial changes, Goryeo declared itself to be a vassal state of Jin in 1126.[86][87] After that, peace was maintained and Jin never actually did invade Goryeo.

Tension continued through the 12th century and into the 13th century, when the Mongol invasions started. After a series of battles, Goryeo capitulated to the Mongols, with the direct dynastic rule of Goryeo monarchy.[78]

Buddhism in medieval Korea evolved in ways which rallied support for the state.[88]

Initially, the new Seon schools were regarded by the established doctrinal schools as radical and dangerous upstarts. Thus, the early founders of the various "nine mountain"[89] monasteries met with considerable resistance, repressed by the long influence in court of the Gyo schools. The struggles which ensued continued for most of the Goryeo period, but gradually the Seon argument for the possession of the true transmission of enlightenment would gain the upper hand.[89] The position that was generally adopted in the later Seon schools, due in large part to the efforts of Jinul, did not claim clear superiority of Seon meditational methods, but rather declared the intrinsic unity and similarities of the Seon and Gyo viewpoints.[90] Although all these schools are mentioned in historical records, toward the end of the dynasty, Seon became dominant in its effect on the government and society, and the production of noteworthy scholars and adepts. During the Goryeo period, Seon thoroughly became a "religion of the state," receiving extensive support and privileges through connections with the ruling family and powerful members of the court.[91] Although Buddhist takes primary place, Taoism was worshiped in some temples, as did shamanism.[92]

Although most of the scholastic schools waned in activity and influence during this period of the growth of Seon, the Hwaeom school continued to be a lively source of scholarship well into the Goryeo, much of it continuing the legacy of Uisang and Wonhyo.[92] In particular the work of Gyunyeo (均如; 923-973) prepared for the reconciliation of Hwaeom and Seon,[93] with Hwaeom's accommodating attitude toward the latter.[94] Gyunyeo's works are an important source for modern scholarship in identifying the distinctive nature of Korean Hwaeom.[94]

Another important advocate of Seon/Gyo unity was Uicheon. Like most other early Goryeo monks, he began his studies in Buddhism with the Hwaeom school. He later traveled to China, and upon his return, actively promulgated the Cheontae (天台宗, or Tiantai in Chinese) teachings, which became recognized as another Seon school. This period thus came to be described as "five doctrinal and two meditational schools" (ogyo yangjong). Uicheon himself, however, alienated too many Seon adherents, and he died at a relatively young age without seeing a Seon-Gyo unity accomplished.

Gwangyeongseopum Byeonsangdo, Goryeo buddhist painting.

The most important figure of Seon in the Goryeo was Jinul (知訥; 1158–1210). In his time, the sangha was in a crisis of external appearance and internal issues of doctrine. Buddhism had gradually become infected by secular tendencies and involvements, such as fortune-telling and the offering of prayers and rituals for success in secular endeavors. This kind of corruption resulted in the profusion of increasingly larger numbers of monks and nuns with questionable motivations. Therefore, the correction, revival, and improvement of the quality of Buddhism were prominent issues for Buddhist leaders of the period.

Jinul sought to establish a new movement within Korean Seon, which he called the "samādhi and prajñā society",[95] whose goal was to establish a new community of disciplined, pure-minded practitioners deep in the mountains.[90] He eventually accomplished this mission with the founding of the Seonggwangsa monastery at Mt. Jogye (曹溪山).[90] Jinul's works are characterized by a thorough analysis and reformulation of the methodologies of Seon study and practice. One major issue that had long fermented in Chinese Seon, and which received special focus from Jinul, was the relationship between "gradual" and "sudden" methods in practice and enlightenment. Drawing upon various Chinese treatments of this topic, most importantly those by Zongmi (780-841) and Dahui (大慧; 1089–1163),[96] Jinul created a "sudden enlightenment followed by gradual practice" dictum, which he outlined in a few relatively concise and accessible texts.[97] From Dahui, Jinul also incorporated the gwanhwa (觀話) method into his practice.[95] This form of meditation is the main method taught in Korean Seon today. Jinul's philosophical resolution of the Seon-Gyo conflict brought a deep and lasting effect on Korean Buddhism.

The general trend of Buddhism in the latter half of the Goryeo was a decline due to corruption, and the rise of strong anti-Buddhist political and philosophical sentiment.[98] However, this period of relative decadence would nevertheless produce some of Korea's most renowned Seon masters. Three important monks of this period who figured prominently in charting the future course of Korean Seon were contemporaries and friends: Gyeonghan Baeg'un (景閑白雲; 1298–1374), Taego Bou (太古普愚; 1301–1382) and Naong Hyegeun (懶翁慧勤; 1320–1376). All three went to Yuan China to learn the Linji (臨濟 or Imje in Korean) gwanhwa teaching that had been popularized by Jinul. All three returned, and established the sharp, confrontational methods of the Imje school in their own teaching. Each of the three was also said to have had hundreds of disciples, such that this new infusion into Korean Seon brought about considerable effect. Despite the Imje influence, which was generally considered to be anti-scholarly in nature, Gyeonghan and Naong, under the influence of Jinul and the traditional tong bulgyo tendency, showed an unusual interest in scriptural study, as well as a strong understanding of Confucianism and Taoism, due to the increasing influence of Chinese philosophy as the foundation of official education. From this time, a marked tendency for Korean Buddhist monks to be "three teachings" exponents appeared.

A significant historical event of the Goryeo period is the production of the first woodblock edition of the Tripitaka, called the Tripitaka Koreana. Two editions were made, the first one completed from 1210 to 1231, and the second one from 1214 to 1259. The first edition was destroyed in a fire, during an attack by Mongol invaders in 1232, but the second edition is still in existence at Haeinsa in Gyeongsang province. This edition of the Tripitaka was of high quality, and served as the standard version of the Tripitaka in East Asia for almost 700 years.[99]

According to Goryeosa, Muslims arrived in the peninsula in the year 1024 in the Goryeo kingdom,[102] a group of some 100 Muslims, including Hasan Raza, came in September of the 15th year of Hyeonjong of Goryeo and another group of 100 Muslim merchants came the following year.

Trading relations between the Islamic world and the Korean peninsula continued with the succeeding Goryeo kingdom through to the 15th century. As a result, a number of Muslim traders from the Near East and Central Asia settled down in Korea and established families there. Some Muslim Hui people from China also appear to have lived in the Goryeo kingdom.[103]

With the Mongol armies came the so-called Saengmokin (Semu), or "colored-eye people", this group consisted of Muslims from Central Asia.[104] In the Mongol social order, the Saengmokin occupied a position just below the Mongols themselves, and exerted a great deal of influence within the Yuan dynasty.

It was during this period satirical poems were composed and one of them was the Sanghwajeom, the "Colored-eye people bakery", the song tells the tale of a Korean woman who goes to a Muslim bakery to buy some dumplings.[105]

Small-scale contact with predominantly Muslim peoples continued on and off. During the late Goryeo period, there were mosques in the capital Gaeseong, called Ye-Kung, whose literary meaning is a "ceremonial hall".[107]

One of those Central Asian immigrants to Korea originally came to Korea as an aide to a Mongol princess who had been sent to marry King Chungnyeol of Goryeo. Goryeo documents say that his original name was Samga but, after he decided to make Korea his permanent home, the king bestowed on him the Korean name of Jang Sunnyong.[108] Jang married a Korean and became the founding ancestor of the Deoksu Jang clan. His clan produced many high officials and respected Confucian scholars over the centuries. Twenty-five generations later, around 30,000 Koreans look back to Jang Sunnyong as the grandfather of their clan: the Jang clan, with its seat at Toksu village.[109]

The same is true of the descendants of another Central Asian who settled down in Korea. A Central Asian named Seol Son fled to Korea when the Red Turban Rebellion erupted near the end of the Mongol’s Yuan dynasty.[110] He, too, married a Korean, originating a lineage called the Gyeongju Seol that claims at least 2,000 members in Korea.

Soju was first distilled around the 13th century, during the Mongol invasions of Korea. The Mongols had acquired the technique of distilling Arak from the Muslim World[111] during their invasion of Central Asia and the Middle East around 1256, it was subsequently introduced to Koreans and distilleries were set up around the city of Kaesong. Indeed, in the area surrounding Kaesong, Soju is known as Arak-ju (hangul: 아락주).[112] Under the reign of King Chungryeol, soju quickly became popular drink, while the stationed region of Mongolian troops came to produce high-quality soju, for instance in Andong.[113]

Tripitaka Koreana (팔만대장경) is a Tripitaka with approximately 80,000 Buddhist scripts. The scripts are stored in Haeinsa, South Gyeongsang province. Made in 1251 by Gojong in an attempt to fight away the Mongol invasions by Buddhism. The scripts are kept clean by leaving them to dry outside every year.

Ewer with Cover, first half of the 12th century. Stoneware with underglaze slip decoration and celadon glaze. Celadon ceramics of the Goryeo dynasty (918–1392) are among the most celebrated works of Korean art. Their luminous green color is the result of iron in both the clay and the glaze oxidizing in a reduction kiln. Brooklyn Museum

The ceramics of Goryeo are considered by some to be the finest small-scale works of ceramics in Korean history. Key-fret, foliate designs, geometric or scrolling flowerhead bands, elliptical panels, stylized fish and insects, and the use of incised designs began at this time. Glazes were usually various shades of celadon, with browned glazes to almost black glazes being used for stoneware and storage. Celadon glazes could be rendered almost transparent to show black and white inlays.

While the forms generally seen are broad-shouldered bottles, larger low bowls or shallow smaller bowls, highly decorated celadon cosmetic boxes, and small slip-inlaid cups, the Buddhist potteries also produced melon-shaped vases, chrysanthemum cups often of spectacularly architectural design on stands with lotus motifs and lotus flower heads. In-curving rimmed alms bowls have also been discovered similar to Korean metalware. Wine cups often had a tall foot which rested on dish-shaped stands.

During the Goryeo period, lacquerware with mother-of-pearl inlay reached a high point of technical and aesthetic achievement and was widely used by members of the aristocracy for Buddhist ritual implements and vessels, as well as horse saddles and royal carriages. Inlaid lacquers combine texture, color, and shape to produce a dazzling effect in both large and small objects. Although Korean lacquerware of the Goryeo period was highly prized throughout East Asia, fewer than fifteen examples are known to have survived, one of which is this exquisite box in the Museum's collection. This paucity of material is largely attributable to the fragility of lacquer objects and, to a certain extent, to wars and raids by foreign powers, notably those launched from Japan by Toyotomi Hideyoshi (1536–1598) in the late sixteenth century.

A Korean stoneware cosmetic box with white and black inlay and a celadon glaze, from the Goryeo Dynasty, dated c. 1150–1250

These ceramics are of a hard porcellaneous body with porcelain stone as one of the key ingredients; however, it is not to be confused with porcelain. The body is low clay, quartz rich, high potassia and virtually identical in composition to the Chinese Yueh ceramics which scholars hypothesize occasioned the first production of celadon in Korea. The glaze is an ash glaze with iron colourant, fired in a reduction atmosphere in a modified Chinese-style 'dragon' kiln. The distinctive blue-grey-green of Korean celadon is caused by the iron content of the glaze with a minimum of titanium contaminant, which modifies the color to a greener cast, as can be seen in Chinese Yueh wares. However, the Goryeo potters took the glaze in a different direction than their Chinese forebears; instead of relying solely on underglaze incised designs, they eventually developed the sanggam technique of inlaying black (magnetite) and white (quartz) which created bold contrast with the glaze. Scholars also theorize that this developed in part to an inlay tradition in Korean metalworks and lacquer, and also to the dissatisfaction with the nearly invisible effect of incising when done under a thick celadon glaze.[114]

Jikji, Selected Teachings of Buddhist Sages and Seon Masters, the earliest known book printed with movable metal type, 1377. Bibliothèque Nationale de Paris.

It is generally accepted that the world's first metal movable type was invented in Goryeo during the 13th century by Choe Yun-ui.[115][116][117][118][119] However, according to the Chinese scholar Pan Jixing, the earliest forms of metal movable type were first developed in China: a simple form of metal movable type existed in China as early as the 11th century, but it was not developed enough to print more than a few characters at a time.[4][5]Sangjeong Gogeum Yemun were printed with the movable metal type in 1234. Technology in Korea took a big step in Goryeo and strong relation with the Song dynasty contributed to this. In the dynasty, Korean ceramics and paper, which come down to now, started to be manufactured.

During the late Goryeo Dynasty, Goryeo was at the cutting edge of shipboard artillery. In 1356 early experiments were carried out with gunpowder weapons that shot wood or metal projectiles. In 1373 experiments with incendiary arrows and "fire tubes" possibly an early form of the Hwacha were developed and placed on Korean warships. The policy of placing cannons and other gunpowder weapons continued well into the Joseon Dynasty and by 1410, over 160 Joseon warships had cannons on board. Choe Mu-seon, a medieval Korean inventor, military commander and scientist who introduced widespread use of gunpowder to Korea for the first time and creating various gunpowder based weapons.

^Lee, Ki-Baik (1984). A New History of Korea. Cambridge, Massachusetts: Harvard University Press. p. 103. ISBN067461576X. "When Parhae perished at the hands of the Khitan around this same time, much of its ruling class, who were of Koguryŏ descent, fled to Koryŏ. Wang Kŏn warmly welcomed them and generously gave them land. Along with bestowing the name Wang Kye ("Successor of the Royal Wang") on the Parhae crown prince, Tae Kwang-hyŏn, Wang Kŏn entered his name in the royal household register, thus clearly conveying the idea that they belonged to the same lineage, and also had rituals performed in honor of his progenitor. Thus Koryŏ achieved a true national unification that embraced not only the Later Three Kingdoms but even survivors of Koguryŏ lineage from the Parhae kingdom."

^Breuker 2010, pp. 220-221. "The Jurchen settlements in the Amnok River region had been tributaries of Koryŏ since the establishment of the dynasty, when T'aejo Wang Kŏn heavily relied on a large segment of Jurchen cavalry to defeat the armies of Later Paekche. The position and status of these Jurchen is hard to determine using the framework of the Koryŏ and Liao states as reference, since the Jurchen leaders generally took care to steer a middle course between Koryŏ and Liao, changing sides or absconding whenever that was deemed the best course. As mentioned above, Koryŏ and Liao competed quite fiercely to obtain the allegiance of the Jurchen settlers who in the absence of large armies effectively controlled much of the frontier area outside the Koryŏ and Liao fortifications. These Jurchen communities were expert in handling the tension between Liao and Koryŏ, playing out divide-and-rule policies backed up by threats of border violence. It seems that the relationship between the semi-nomadic Jurchen and their peninsular neighbours bore much resemblance to the relationship between Chinese states and their nomad neighbours, as described by Thomas Barfield."

^Hatada, Smith Jr & Hazard 1969, p. 51f: "From ancient times, Korea has been directly affected by changes occurring in the adjoining part of Asia, and her fate has been intertwined with continental Asiatic affairs. For example, it was during the chaotic period on the continent coinciding with the end of T'ang and the Five Dynasties (907-960) in China that Wang Kŏn was able to found the new dynasty without interference from the continent. But once the unification of Korea was completed, tribute was immediately sent to the various states of the Five Dynasties, and when Sung unified China in 960, Koryŏ rendered tribute to Sung. In each case this was necessary to enhance the authority of the ruler of Korea by the support of the ruler of China. ..."

^ abcEbrey & Walthall 2014, [2], p. 171, at Google Books: "In the case of the Khitan Liao, two decades of military confrontation ended in 1020 with a negotiated settlement to transfer Goryeo’s vassal status from the Song to the Liao." "Liao forces invaded Goryeo territory in 993. ... the Khitans negotiated a peace that forced Goryeo to adopt the Liao calendar and end tributary relations with Song ... In 1010, on the pretext that the rightful king had been deposed without the approval of the Liao court, the Khitan emperor personally led an attack that culminated in the burning of the Goryeo capital. Several other confrontations followed until Goryeo reaffirmed its tributary relationship with Liao in 1020."

^Hyun 2013, p. 106: "the Khitan army attacked Goryeo, who was forced to accept the status of a Liao tributary in 994."

^Hatada, Smith Jr & Hazard 1969, p. 52: "In the thirteenth year of the reign of King Sŏngjong (994), Koryŏ submitted to the Khitan and adopted their calendar".

^Simons 1995, p. 95: "In 994, during the reign of King Songjong, Koryo was forced to acknowledged the dominance of Khitan".

^Yun 1998, p.64: "By the end of the negotiation, Sô Hûi had ... ostensibly for the purpose of securing safe diplomatic passage, obtained an explicit Khitan consent to incorporate the land between the Ch’ôngch’ôn and Amnok Rivers into Koryô territory."

^Hyun 2013, p.106: "Even though the Goryeo court agreed to set up tribute exchanges with the Liao court, that same year [=994] it also sent an envoy to the Song court to appeal, but in vain, for military assistance against the Khitan."

^Bowman 2013, p. 203: "Fearful of plots against him, Mokchong summons Kang Cho from his administrative post in the northwest. However, Kang Cho himself engineers a successful coup in which Mokchong is assassinated."

^ abEbrey & Walthall 2014, [3], p. 171, at Google Books: "In 1010, on the pretext that the rightful king had been deposed without the approval of the Liao court, the Khitan emperor personally led an attack that culminated in the burning of the Goryeo capital."

^ abSimons 1995, p. 93: "a second Liao incursion resulted in heavy losses, the sacking of Kaesong, and the imposition of Liao suzerainty over the Koryo state." p. 95: "a prelude to more invasions during the reign of King Hyonjong (1010-1031) and the occupation of Kaesong, the Koryo capital."

^Hatada, Smith Jr & Hazard 1969, p. 52: "in the reign of King Hyŏnjong (1010-1031) there were numerous Khitan invasions, and even the capital Kaesŏng was occupied."

^ abcTwitchett, Denis C.; Franke, Herbert; Fairbank, John King. The Cambridge History of China: Volume 6, Alien Regimes and Border States, 907-1368. Cambridge University Press. pp. 111–112. ISBN9780521243315. Retrieved 30 July 2016. In 1018 a huge new expeditionary force was mobilized by the Khitan and placed under the command of Hsiao P'ai-ya. The army crossed the Yalu late in 1018 but was ambushed by a superior Koryŏ force, suffering severe losses. The Koryŏ army had also cut their line of retreat, and so Hsiao P'ai-ya marched south, planning to take the capital Kaegyŏng, as in 1011. But this time the Koreans had prepared defenses around the capital, and the Khitan, constantly harried by Korean attacks, were forced to retreat toward the Yalu. At Kuju, between the Ch'a and T'o rivers, they were encircled and attacked by the main Koryŏ forces, which almost annihilated the Khitan army. Only a few thousand men managed to return to the Liao border.

^Twitchett & Tietze 1994, p.112: "When in 1031 Hyǒnjong died, his son and successor Wang Hǔm (Tǒkchong; r. 1031-4) was invested as king by the Liao court. From this date until almost the end of the Liao, Koryǒ remained a loyal vassal, and peace prevailed between the two states."

^Breuker, Remco E. Establishing a Pluralist Society in Medieval Korea, 918-1170: History, Ideology and Identity in the Koryŏ Dynasty. BRILL. p. 245. ISBN9004183256. Retrieved 30 July 2016. The absence of official contacts did not interrupt unofficial relations from blossoming. From the third decade of the eleventh century onwards, the Standard Koryŏ history records the arrival of hundreds of merchants each year and tens of well-educated Song émigrés, a situation which continued until the twelfth century. Relations between Koryŏ and the Song, then, from the 1030s to the 1080s were intensive and fruitful, except on the level of the state.

^Hyun 2013, p.3: "The Goryeo ... sent tributary missions to the Later Tang, Later Jin, Later Han and Later Zhou successively, which Goryeo officials recognized as proper successors of the Tang, the new "centers" of China."

^Franke 1994, p. 229: "the king of Koryŏ declared himself a vassal of Chin in the summer of 1126."

^Ebrey & Walthall 2014, [4], p. 171, at Google Books: "In the case of the Jurchen Jin, the [Goryeo] court decided to transfer its tributary relationship from the Liao to Jin before serious violence broke out." Also p.172: "Koryŏ enrolled as a Jin tributary".

^Vermeersch, Sem. (2008). The Power of the Buddhas: the Politics of Buddhism during the Koryŏ Dynasty (918-1392), p. 3.